CN1438349A

CN1438349A - Method for producing rare-earth metal screw-rod

Info

Publication number: CN1438349A
Application number: CN03119658A
Authority: CN
Inventors: 王龙妹; 杜挺; 刘浏
Original assignee: Central Iron and Steel Research Institute
Current assignee: Central Iron and Steel Research Institute
Priority date: 2003-03-19
Filing date: 2003-03-19
Publication date: 2003-08-27
Anticipated expiration: 2023-03-19
Also published as: CN100381596C

Abstract

The invention belongs to smelting and processing field, especially field, especially refers to the smelting and process of rare earth metal. The craft process includes adjuvant, smelting and casting ingot and heat squeeze forming. The rare earth metal material of La 40-90%, Y 30-60% and Ce 45-58% mixes with compound rare earth respectively, smelting and casting ingot is carries on under protection of gas, when being smelted, adds in pre-smelted protection residues, the residues are chloride series and oxide serial. The pressure mould is to be preheated to 450-650 deg.C, the rare earth metal casting ingot is to be heated to 250-450 deg.C and controls the outputting speed of silk when pressing.

Description

The production method of rare-earth metal wire rod

Technical field

The invention belongs to Metal Melting and manufacture field, particularly the production of rare-earth metal wire material bar.

Background technology

In field of iron and steel, rare earth metal obtains more and more widely application as trace element or additive.Usually, rare earth element adds in the steel, can reduce P in the steel, S and inclusion content, purify crystal boundary, simultaneously, rare earth element can also change the form and the distribution of steel inclusion, even the composition of change inclusion, the plasticity and toughness that these effects can both improve steel effectively improve processing characteristics.

Rare earth metal adds the method in the steel, more typically has two kinds, and the one, the rare earth metal rod is hung in die casting; The one, in casting process, utilize wire feeder with rare-earth metal wire being fed in crystallizer or the tundish gradually, claim to feed a silk method.This is at present rare earth metal to be added advanced and satisfactory method in the steel.But the subject matter that this method exists is to feed in the silk process at continuous casting, the fracture of wire phenomenon often occurs, causes the rare earth metal skewness of feeding etc., the major cause of fracture of wire be the relatively poor and purity of the plasticity and toughness of rare-earth metal wire not high due to.

Summary of the invention

The object of the present invention is to provide a kind of rare earth metal purity height and the plasticity and toughness production method of rare-earth metal wire rod preferably.

At above-mentioned purpose.The production method of rare-earth metal wire rod of the present invention, its technological process comprise that batching, melting ingot casting, hot extrusion become a useful person.

One, batching

Rare-earth metal wire rod of the present invention, the Chemical Composition of its raw material (wt%) are any in following three kinds of compositions:

A, ∑ RE 〉=99.6%, wherein La is 40～90%, all the other are other mishmetal beyond the La;

B, ∑ RE 〉=99.6%, wherein Y is 30～60%, all the other are other mishmetal beyond the Y;

C, ∑ RE 〉=99.0%, wherein Ce is 45～58%, all the other are other mishmetal beyond the Ce.

Prepare burden according to above-mentioned Chemical Composition

Two, melting ingot casting

Melting is carried out in the smelting device of routine He under the protective atmosphere, but the high and anti-rare earth of the liner of smelting device (furnace lining) material requirements purity corrodes.

To add in the smelting device by the rare-earth metal material that the Chemical Composition scope is equipped with, the upgrading covering slag that will melt in advance simultaneously also adds in the smelting device, as the insulating covering agent of melting.

The upgrading covering slag has two kinds: muriate slag system and oxide compound slag system.

The Chemical Composition of muriate slag system (wt%) is B ₂O ₃1.0～10.0%, MgO 0.5～15%, Na ₂O+K ₂O 1.0～8.0%, F0.5～10%, and C0.5～6.0%, surplus is muriate.

Muriate is KCl, NaCl, MgCl ₂, FeCl ₂, CaCl ₂, MnCl ₂In any or any two above sum.

The Chemical Composition of oxide compound slag system (wt%) is: SiO2 15～35%, and CaO+MgO 20～35%, Al ₂O ₃1～12%, B ₂O ₃1.0～10%, Na ₂O+K ₂O 1.0～8.0%, F2.0～10.0%, and C1.0～7.0%, surplus is oxide compound.

Oxide compound is: Ce ₂O ₃, Mn ₂O ₃, Cao, Mgo, Na ₂O, B ₂O ₃, Al ₂O ₃In any or any two above sum.

Raw material and upgrading covering slag all melt, and scum after fully stirring, and are cast into ingot immediately.Casting is also carried out under protective atmosphere.

The upgrading covering slag that adopts during melting can be in muriate slag system or the oxide compound slag system any.

Three, hot-pressed

The rare earth metal ingot casting that casting is good is squeezed into a material or bar in extrusion machine.Before the extruding, the rare earth metal ingot casting is heated to 250～450 ℃ in process furnace, the pressing mold of extrusion machine also is preheated to 450～650 ℃, and ingot casting heating and whole extrusion process are all carried out in protective atmosphere.

During extruding, the ingot casting that heats is put into the good pressing mold of extrusion machine preheating, ingot casting is squeezed into a material or bar.

During extruding, when rare-earth metal wire material diameter was 1～5mm, the wire vent speed control during extruding was at 0.1～2.0m/s.When rare earth metal diameter of rod 〉=6mm, the rod speed that goes out during extruding is controlled at 1.5～2.5m/s.

(diameter≤6mm), its tensile strength 〉=160MPa characterize alternating bending number of times 〉=25 time of plasticity and toughness to adopt the rare-earth metal wire that the present invention produces.

Compared with prior art, the present invention has following advantage:

1. rare-earth metal wire of the present invention, bar have good plasticity and toughness.The upgrading covering slag that the present invention is added when steel-smelting has the ability of acid non-soluble substance folder matter such as very strong absorption fused raw material middle-weight rare earths metal oxide, silicate; the purity of molten rare earth metal is improved greatly; in addition; because melting, casting are all carried out in protective atmosphere; gases such as oxygen in the molten rare earth metal also reduce greatly; for above-mentioned reasons, the plasticity and toughness of rare earth metal significantly improve.

2. because the rare-earth metal wire rod plasticity and toughness that the inventive method is produced are good, therefore, feed in the silk process not fracture of wire at continuous casting, both improved and fed silk efficient, also guaranteed rare earth metal uniform distribution in the continuous casting ingot, guaranteed the quality of ingot casting.

Embodiment:

According to the production method of rare-earth metal wire rod of the present invention, and, three batches of rare-earth metal wire rods have been prepared according to batching, melting ingot casting, hot extrusion forming process process.The Chemical Composition of three batches of batchings is listed in the table 1.Adopted during melting three to correct the Chemical Composition of matter covering slag as shown in table 2.Immediately be cast into ingot after the melting, melting, casting are all carried out under protective atmosphere.During the ingot casting extruding, ingot casting Heating temperature, pressing mold preheating temperature and wire vent rod speed are as shown in table 3.After the rare-earth metal wire rod is squeezed into finished product, measured the Chemical Composition of product, its result lists table 4 in.Also measured the intensity and the plasticity and toughness of the finished product simultaneously, measurement result is as shown in table 5, has also listed the specification of product in the table 3.

The Chemical Composition (wt%) of table 1 embodiment rare-earth metal material

The Chemical Composition of table 2 embodiment upgrading covering slag

Lot number	Chemical Composition (wt%)
	Chemical Composition (wt%)										Slag system	?B ₂O ₃	?MgO	?SiO ₂	?Na ₂O +K ₂O	??CaO+ ??MgO	??F	?AL ₂O ₃	??C	Muriate or oxygen or thing
	??1	The muriate slag system	??9.3	??6.3		??7.3		??5.8		??4.0	Slag system	?B ₂O ₃	?MgO	?SiO ₂	?Na ₂O +K ₂O	??CaO+ ??MgO	??F	?AL ₂O ₃	??C	Muriate or oxygen or thing	Surplus is KCl
??2	??1	The muriate slag system	??9.3	??6.3		??7.3		??5.8		??4.0	The muriate slag system	??2.9	??13.2		??4.8		??7.5		??3.8	Surplus is CaCl ₂	Surplus is KCl
??2	??3	The muriate slag system	??7.6		?32.1	??5.9	??27.1	??4.1	??4.8	?5.7	The muriate slag system	??2.9	??13.2		??4.8		??7.5		??3.8	Surplus is CaCl ₂	Surplus is Ce ₂O ₃

Table 3 embodiment hot extrusion parameter

The Chemical Composition (wt%) of table 4 embodiment the finished product

Table 5 embodiment the finished product service check result

^*Annotate: the conduct steel-making that former Ministry of Metallurgical Industry issues adds the standard of performance of the rare-earth metal wire of rare earth.

Claims

1, a kind of production method of rare-earth metal wire rod, technological process comprise batching, melting ingot casting, hot-pressed, it is characterized in that:

1. prepare burden

During batching, prepare burden by in the Chemical Composition (wt%) of following three kinds of rare-earth metal materials any:

A, ∑ RE 〉=99.6%, wherein La is 40～90%, all the other are other mixing beyond the La Rare earth;

B, ∑ RE 〉=99.6%, wherein Y is 30～60%, all the other are that Y other mixing in addition is rare Soil;

C, ∑ RE 〉=99.0%, wherein Ce is 45～58, all the other are that Ce other mixing in addition is rare Soil;

2. melting ingot casting

When raw material adds smelting device, add the upgrading covering slag of fritting, promptly the upgrading covering slag with fritting is an insulating covering agent; This covering slag be in chlorination slag system and the oxidation slag system any, melting, ingot casting all carry out under protective atmosphere;

3. hot-pressed

During hot extrusion, the Heating temperature of rare earth metal ingot casting is 250～450 ℃, and the extrusion machine pressing mold need be preheated to 450～650 ℃, and ingot casting heating and whole extrusion process are all carried out under protective atmosphere.

2, production method according to claim 1 is characterized in that the upgrading covering slag is the muriate slag system, and its Chemical Composition (wt%) is B ₂O ₃1.0～10.0%, MgO 0.5～15%, Na ₂O+K ₂O1.0～8.0%, F0.5～10%, C0.5～6.0%, surplus is muriate.

3, production method according to claim 1 is characterized in that the upgrading covering slag is the oxide compound slag system, concrete Chemical Composition (wt%) SiO2 15～35%, and CaO+MgO 20～35%, Al ₂O ₃1～12%, B ₂O ₃1.0～10%, Na ₂O+K ₂O 1.0～8.0%, F2.0～10.0%, and C1.0～7.0%, surplus is oxide compound.

4, production method according to claim 1 is characterized in that the diameter when the rare-earth metal wire that pushes is 1～5mm, and the wire vent speed control of extruding is at 0.1～2m/s.

5, production method according to claim 1 is characterized in that the rod speed that goes out of extruding is controlled at 1.5～2.5m/s as the diameter 〉=6mm of the rare earth metal rod of extruding.

6, according to claim 1,2 described production methods, its feature is KCl, NaCl, MgCl at muriate ₂, FeCl ₂, CaCl ₂, MnCl ₂In any or any two above sum.

7, production method according to claim 1, its feature is at oxide compound Ce ₂O ₃, Mn ₂O ₃, Cao, Mgo, Na ₂O, B ₂O ₃, Al ₂O ₃In any or any two above sum.